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Biomedical subjects

P Garg

Publications and source records attributed to P Garg.

At least 37 records · Page 2Linked to original sources
PubMed2001

Treatment and outcome of nocardia keratitis.

OBJECTIVE: To report our experience in treatment and outcome ofNocardia keratitis. METHODS: Medical and microbiology records of seven cases of culture-provenNocardia keratitis seen between January 1997 and March 1999 were reviewed retrospectively. In all patients, corneal scrapings were obtained for direct microscopic evaluation and culture. Drug sensitivity was determined by the Kirby-Bauer disk-diffusion method. The minimum inhibitory concentration of ciprofloxacin and amikacin for these isolates was determined by agar dilution method. Response to medical therapy and the end result were analyzed. RESULTS: By the in vitro Kirby-Bauer disk-diffusion techniques, all isolates were sensitive to amikacin; six of these isolates were sensitive to gentamicin and four were sensitive to ciprofloxacin. The minimum inhibitory concentration (MIC) of amikacin for all isolates by the agar-dilution technique was well below the MIC breakpoint forNocardia resistance, whereas the MIC of ciprofloxacin was above the MIC breakpoint forNocardia resistance. All patients responded to medical therapy. The corneal infection resolved in three patients after treatment with ciprofloxacin, in one patient after fortified gentamicin, and in three patients after fortified amikacin. Outcome details were available for six patients. There was good visual recovery in four patients, with visual acuity of 20/25 or better in three. The cornea of two patients developed nonvascularized scars, and in four patients in whom the infiltrates were peripheral, vascularization was seen. CONCLUSIONS: Although patients ofNocardia keratitis may respond to other antibiotics, amikacin appears to be a drug of choice. In this small series, when appropriate therapy was initiated,Nocardia keratitis resolved promptly with good visual recovery.

Amikacin↗
PubMed2001

Aspergillus fumigatus keratitis with wreath pattern infiltrates.

PURPOSE: To report a case of Aspergillus fumigatus keratitis with clinical features simulating Nocardia keratitis and to highlight the utility of microbiologic investigation in the successful management of infectious keratitis. METHOD: Case report. RESULTS: A 62-year-old man presented with complaints of pain, redness, and watering of 10 days' duration in his right eye. Direct microscopic observation of smears of corneal scrapings revealed a fungal etiology. The patient was treated with 5% natamycin eye drops and 1% atropine sulphate eye drops and was advised to visit the hospital for observation. During his visit to the hospital on day 10 after medication, the eye demonstrated a wreath pattern corneal infiltrate that simulated Nocardia keratitis. The fungus grown from culture of corneal scraping was identified as A. fumigatus. CONCLUSION: This report highlights the significance of subjecting corneal scrapings from suspected cases of infectious keratitis to microbiologic evaluation and emphasizes the fact that a complete microbiologic work-up helps in establishing a definitive etiologic diagnosis and initiating specific antimicrobial therapy.

Antifungal Agents↗
PubMed2001

Impact of underuse, overuse, and discretionary use on geographic variation in the use of coronary angiography after acute myocardial infarction.

BACKGROUND: Geographic variation in the use of medical procedures has been well documented. However, it is not known whether this variation is due to differences in use when procedures are indicated, discretionary, or contraindicated. OBJECTIVES: To examine whether use of coronary angiography after acute myocardial infarction (AMI) according to appropriateness criteria varied across geographic regions and whether underuse, overuse, or discretionary use accounted for variation in overall use. DESIGN: Retrospective cohort study using data from the Cooperative Cardiovascular Project. SETTING: Ninety-five hospital referral regions. PATIENTS: There were 44,294 Medicare patients hospitalized with AMI during 1994 or 1995, classified according to appropriateness for angiography. MAIN OUTCOME MEASURE: Variation in use of angiography, as measured by the difference between high and low rates of use across regions. RESULTS: Across regions, variation in the use of angiography was similar for indications judged necessary; appropriate, but not necessary; or uncertain. Variation was lowest for indications judged unsuitable (difference between high rate and low rate across regions = 16.3%; 95% CI = 12.6%; 20.6%). The primary cause of variation in the overall rate of angiography was due to use for indications judged appropriate, but not necessary or uncertain. When variation associated with these indications was accounted for, the difference between the resulting high and low overall rates was 10.8% (9.4%, 12.4%). In contrast, variation in the overall rate remained high when underuse in necessary situations or overuse in unsuitable situations was accounted for. CONCLUSIONS: Across regions, practice was more similar for patients categorized unsuitable for angiography than for patients with other indications. Variation in overall use of angiography appeared to be driven by utilization for discretionary indications rather than by underuse or overuse. If equivalent rates across geographic areas are judged desirable, then greater effort must be directed toward defining care for patients with discretionary indications.

Aged↗
PubMed2001

Comparison of antibiogram, virulence genes, ribotypes and DNA fingerprints of Vibrio cholerae of matching serogroups isolated from hospitalised diarrhoea cases and from the environment during 1997-1998 in Calcutta, India.

This study identified 17 matching serogroups of Vibrio cholerae belonging to serogroups other than O1 and O139 isolated from human cases and from the environment during a concurrent clinical and environmental study conducted in Calcutta, a cholera endemic area. Isolates within these matching serogroups were compared by various phenotypic and genotypic traits to determine if the environment was the source of the organisms associated with the disease. Clinical strains of V. cholerae were resistant to a greater number of drugs and exhibited multi-drug resistance compared with their environmental counterparts. Except for the presence of the genes for the El Tor haemolysin and the regulatory element ToxR in most of the strains of V. cholerae examined, non-O1, non-O139 V. cholerae strains lacked most of the other known virulence traits associated with toxigenic V. cholerae O1 or O139. Restriction fragment-length polymorphism of virulence-associated genes, ribotypes and DNA fingerprints of strains of matched serogroups showed considerable diversity, although some gene polymorphisms and ribotypes of a few strains of different serogroups were similar. It is concluded that despite sharing the same serogroup, environmental and clinical isolates were genetically heterogeneous and were of different lineages.

Blotting, Southern↗
PubMed2001

Concomitant infection of enterotoxigenic Escherichia coli in an outbreak of cholera caused by Vibrio cholerae O1 and O139 in Ahmedabad, India.

In Ahmedabad, a major city in the state of Gujarat, India, an outbreak of acute secretory diarrhea caused by Vibrio cholerae O1 Ogawa El Tor, V. cholerae O139, and multiple serotypes of enterotoxigenic Escherichia coli (ETEC) occurred in January 2000. All of the representative V. cholerae O1 and O139 isolates examined harbored the ctxA gene (encoding the A subunit of cholera toxin) and the El Tor variant of the tcpA gene (encoding toxin-coregulated pilus). ETEC isolates of different serotypes were positive for the elt gene, encoding heat-labile enterotoxin. To further understand the molecular characteristics of the pathogens, representative isolates were examined by ribotyping and pulsed-field gel electrophoresis (PFGE). Ribotyping showed that the isolates of V. cholerae O1 Ogawa exhibited a pattern identical to that of the prevailing clone of O1 in areas where cholera is endemic in India, and all of the O139 isolates were identical to the BII clone of V. cholerae O139. PFGE of the representative O1 Ogawa isolates exhibited an identical pattern, comparable to the H pattern of the new clone of O1 reported in Calcutta, India. PFGE analysis of the V. cholerae O139 isolates showed identical patterns, but these differed from the PFGE patterns of O139 isolates reported during 1992 to 1997 in Calcutta. ETEC isolates showed genetic heterogeneity among isolates belonging to the same serotype, although the identical PFGE pattern was also observed among ETEC isolates of different serotypes. Antibiograms of the isolates were unusual, because all of the O139 isolates were resistant to nalidixic acid. Likewise, all of the E. coli isolates showed resistance to ciprofloxacin, norfloxacin, and nalidixic acid. This is a unique outbreak, and we believe that it is the first in which V. cholerae and ETEC were concomitantly involved.

Anti-Bacterial Agents↗
PubMed2001

Evaluation of immunoperoxidase staining technique in the diagnosis of Acanthamoeba keratitis.

PURPOSE: We describe a simple procedure of Immunoperoxidase (IP) technique, using indigenously raised antibody, to screen corneal scrapings for Acanthamoeba cysts and trophozoites. This study sought to determine the utility of this test in the diagnosis of Acanthamoeba keratitis. METHODS: A high titre polyclonal antibody against a local clinical isolate (axenic) of Acanthamoeba species (trophozoite lysate antigen) was raised in rabbits and used for standardization of IP technique for corneal scrapings. Twenty two smears of corneal scrapings, collected from patients showing Acanthamoeba cysts in corneal scrapings stained with calcofluorwhite (pool-1) and patients showing no cysts in similar scrapings (pool-2), were coded and stained by IP technique by a masked technician. All 22 patients had also been tested for bacteria, fungus, and Acanthamoeba in their corneal scrapings by smears and cultures. IP stained smears were examined for organisms including cysts and trophozoites of Acanthamoeba and background staining by two observers masked to the results of other smears and cultures. The validity of the IP test in detection of Acanthamoeba cysts and trophozoites was measured by sensitivity, specificity, positive predictive value and negative predictive value in comparison (McNemar test for paired comparison) with calcofluor white staining and culture. RESULTS: Based on the readings of observer 1 and compared to calcofluor white staining, the IP test had a sensitivity of 100%, a specificity of 94%, positive predictive value of 80% and negative predictive value of 100%. When compared to culture, the values were 83%, 100%, 100% and 94% respectively. Trophozoites missed in calcofluor white stained smears, were detected in 2 out of 6 cases of culture-positive Acanthamoeba keratitis. The Kappa coefficient of interobserver agreement was determined as fair (30.4%). CONCLUSION: The immunoperoxidase technique is a simple and useful test in the diagnosis of Acanthamoeba keratitis. This can supplement the culture results.

Acanthamoeba↗
PubMed2000

Persistent changes in myocardial glucose metabolism in vivo during reperfusion of a limited-duration coronary occlusion.

BACKGROUND: Rapid reperfusion of an occluded coronary artery salvages regional mechanical function, but this benefit may not be realized for hours or days because of postischemic stunning. Recovery from stunning is incompletely understood but may involve adaptive changes in heart glucose metabolism. METHODS AND RESULTS: To examine whether reversible coronary occlusion produces sustained changes in regional glucose metabolism in vivo, we performed a 20-minute left coronary artery occlusion followed by 24 hours of open-artery reperfusion in intact rats. Coronary occlusion produced stunning of the anterolateral left ventricle that resolved over 24 hours. When examined at 24 hours, reperfused regions were fully contractile and viable by vital staining and microscopy but demonstrated 25% reduction in blood flow and 50% increased uptake of circulating glucose, as estimated by in vivo [(13)N]NH(3) and [(18)F]fluorodeoxyglucose (FDG) tracer uptake. Reperfused regions had largely inactive glycogen synthase, low rates of glycogen synthesis, and persistent 50% glycogen depletion but increased flux of plasma [1-(13)C]glucose into myocardial [3-(13)C]alanine, indicating preferential shunting of imported glucose away from storage and into glycolysis. CONCLUSIONS: Sustained increases in regional glycolytic consumption of circulating glucose occur during reperfusion of a limited-duration coronary occlusion. This suggests a role for glycolytic ATP in the recovery from postischemic stunning in vivo. Furthermore, [(13)N]NH(3) /FDG regional mismatch may constitute a clinically accessible late metabolic signature of regional myocardial ischemia.

Adenosine Triphosphate↗
PubMed2000

Diversity in the arrangement of the CTX prophages in classical strains of Vibrio cholerae O1.

This study reports the results of a molecular analysis of the CTX prophages in classical biotype strains of Vibrio cholerae O1 of clinical origin isolated between 1970 and 1979 in India. All strains were sensitive to group IV classical phage and polymyxin B but resistant to group 5 El Tor phage. These phenotypic traits are consistent to that exhibited by the classical biotype. PCR studies reconfirmed their biotype assignment and showed the presence of intact CTX prophages and the presence of the recently described toxin linked cryptic plasmid. Restriction fragment length polymorphism of rRNA genes and pulsed-field gel electrophoresis showed clonal diversity among the strains. The most notable observation was the finding that one strain (GP13) has three CTX prophages while another (GP147) has four CTX prophages. This is the first time heterogeneity is reported in the arrangement of the CTX prophages among classical strains of V. cholerae O1.

Bacteriophage Typing↗
PubMed2000

Aspergillus flavus keratitis after laser in situ keratomileusis.

PURPOSE: To report a case of fungal keratitis caused by Aspergillus flavus after laser in situ keratomileusis surgery. METHODS: Case report. A 24-year-old woman developed pain, redness, decreased vision, and an infiltrate posterior to the corneal flap in her right eye 3 days after laser in situ keratomileusis. On referral, approximately 3 weeks after laser in situ keratomileusis, examination of the right eye revealed light perception vision, a large full-thickness corneal infiltrate, and hypopyon. Corneal scrapings were taken for direct microscopic examination and culture. RESULTS: Corneal scraping revealed the presence of fungal filaments in smears and in culture. The fungus was identified as A. flavus. Intensive topical natamycin and systemic ketoconazole therapy was initiated. Despite intensive medical treatment, the infiltrate progressed and the patient was subjected to a therapeutic penetrating keratoplasty. There was no recurrence of infection after surgery. At last follow-up 4 months after surgery, the eye was quiet with graft edema. CONCLUSION: Fungal keratitis is a rare complication of laser in situ keratomileusis surgery. In a case that does not respond to medical treatment, early surgical intervention must be considered.

Adult↗
PubMed2000

Keratomycosis: clinical and microbiologic experience with dematiaceous fungi.

OBJECTIVE: To assess the significance of dematiaceous fungi in the causation of keratomycosis. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Eighty-eight cases of dematiaceous fungal keratitis seen at the L. V. Prasad Eye Institute, Hyderabad, India from January 1991 through December 1996. INTERVENTION: Only culture-proven cases were analyzed. MAIN OUTCOME MEASURES: Predisposing factors, clinical characteristics, microbiology, treatment methods, and outcome. RESULTS: Of 557 cases of fungal keratitis seen during the study period, dematiaceous fungi were the etiologic agents in 88 (15.7%), after Fusarium in 210 (37.6%) and Aspergillus species in 170 cases (30.4%), respectively. Trauma was the most common predisposing factor (47.7%). Fifty-three eyes (61.3%) had the classical clinical picture of yellow-white, dry raised infiltrate with feathery hyphate edges at initial examination. The characteristic macroscopic pigmentation was seen in only 24 eyes (27.27%). Septate branching fungal filaments were identified in 78 smears (88.63%) on light microscopy, of which 5 (5.7%) also showed the presence of bacteria. Curvularia species dominated the spectrum (22.7%). Treatment was started in 48 eyes with topical antifungal agents, whereas 37 received both oral and topical antifungal agents. Outcome data were available for 68 cases. Forty-nine (72%) responded to medical therapy, whereas 13 eyes required therapeutic penetrating keratoplasty and 6 eyes had to be eviscerated. CONCLUSIONS: This is the largest series of keratitis caused by dematiaceous fungi reported to date. It clearly brings out the clinical importance of this group of corneal infections.

Adolescent↗
PubMed2000

Fungal keratitis after laser in situ keratomileusis.

A 22-year-old woman presented with pain, redness, watering, and decrease in vision in her left eye 15 days after laser in situ keratomileusis for myopia. Slitlamp examination showed a central full-thickness infiltrate with hyphate edges. Microscopic examination of corneal scrapings from the edge and underneath the flap showed fungal filaments, and the growth on culture media was identified as Scedosporium apiospermum.

Adult↗
PubMed2000

Expanding multiple antibiotic resistance among clinical strains of Vibrio cholerae isolated from 1992-7 in Calcutta, India.

Antimicrobial susceptibilities of Vibrio cholerae strains isolated from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India for 6 years were analysed to determine the changing trends; 840 V. cholerae strains isolated in 1992-1997 were included in this study. Among V. cholerae serogoup O1 and O139, ampicillin resistance increased from 1992 (35 and 70%, respectively) to 1997 (both serogroups 100%). Resistance to furazolidone and streptomycin was constantly high among V. cholerae O1 strains with gradual increase in resistance to other drugs such as ciprofloxacin, co-trimoxazole, neomycin and nalidixic acid. V. cholerae O139 strains exhibited susceptibilities to furazolidone and streptomycin comparable with those of O1 strains. However, after initial increase in resistance to chloramphenicol and co-trimoxazole, all the V. cholerae O139 strains became susceptible to these two drugs from 1995 onwards. Both V. cholerae O1 and O139 remained largely susceptible to gentamicin and tetracycline. V. cholerae non-O1, non-O139 strains, in contrast, exhibited high levels of resistance to virtually every class of antimicrobial agents tested in this study especially from 1995. Kruskal-Wallis one-way analysis showed that V. cholerae O1 Ogawa serogroup exhibited significant yearly increase in resistance to nine antibiotics followed by non-O1 non-O139 and O139 strains to six antibiotics and two antibiotics respectively. Interesting observation encountered in this study was the dissipation of some of the resistant patterns commonly found among V. cholerae non-O1 non-O139 or O1 serogroups to the O139 serogroup and vice versa during the succeeding years.

Cholera↗
PubMed2000

Penetrating keratoplasty in children.

PURPOSE: To determine the success of penetrating keratoplasty in the presence of various pediatric corneal abnormalities. METHODS: We performed a retrospective study of pediatric corneal grafts at L.V. Prasad Eye Institute, Hyderabad, India. Outcome of pediatric corneal transplantation was evaluated in terms of anatomic and optical success and factors contributing to poor graft survival. On the basis of the corneal pathology, patients were divided into three categories: congenital, acquired nontraumatic, and acquired traumatic. RESULTS: A retrospective analysis of 154 penetrating keratoplasties performed in 140 children, aged 14 years or younger, was done. The average follow-up was 1.3 years (range, 1 week-5 years). Grafts remained clear in 102 (66.2%) of 154 eyes. Clear grafts were achieved in 30 (63.8%) of 47 eyes with congenital opacities, 12 (54.5%) of 22 eyes with opacities from trauma, and 60 (70.6%) of 85 eyes with acquired nontraumatic opacities. Most (26 of 52) of the graft failures occurred during the first 26 weeks after surgery. Survival analysis revealed the probability of a graft remaining clear at the end of 26 weeks as 80% (SE, 3.39%). Poor graft survival could be correlated with those younger than 5 years (p = 0.0341) and performance of anterior vitrectomy (p = 0.0002). Most grafts failed because of allograft rejection (42.3%), infectious keratitis (26.9%), or secondary glaucoma (13.4%). Postoperatively, 53 eyes had > or =20/400 vision, 29 of which had > or =20/50. Vision could not be assessed in 33 eyes because of the young age. CONCLUSION: Whereas anatomic success of pediatric keratoplasty is increasing, optical success continues to remain less than satisfactory. Early surgical intervention and intensive amblyopia therapy may promote visual recovery.

Adolescent↗
PubMed2000

Clinical and microbiological profile of Bacillus keratitis.

PURPOSE: To examine the clinical and microbiological profile of Bacillus keratitis. METHODS: A retrospective review was done of all medical and laboratory records of patients with infectious keratitis in an urban tertiary level eye-care center in South India between January 1991 and June 1997. RESULTS: Nineteen eyes of 17 patients having microbiologically proven Bacillus keratitis were reviewed. The mean age of the patients was 32.64 years (range, 3-70). The duration of symptoms ranged from 1 day to 3 months, with 11 eyes seen within a week of onset of symptoms. Trauma (five eyes), lagophthalmos (two eyes), topical corticosteroid therapy (one eye), bullous keratopathy (two eyes), previous corneal scars (two eyes), and diabetes (one eye) were identified as predisposing factors. Severe corneal features, disproportionate to the duration of symptoms, were present in most of the eyes. Gram stain of corneal scrapings showed variably stained bacilli in eight (42.1%) cases. Polymicrobial infection was present in six eyes (two fungal, four bacterial). Of the 16 isolates tested for in vitro antibiotic susceptibility, 100% were sensitive to gentamicin, 15 (93.75%) were sensitive to ciprofloxacin and norfloxacin, 14 (87.5%) were sensitive to chloramphenicol, and 10 (62.5%) were sensitive to cefazolin. Whereas 12 (63.1%) eyes required only medical therapy, adjunctive procedures were required in seven (36.8%) eyes. The ulcers healed (mean time to healing, 37.4+/-28.6 days) in 16 eyes (lost to follow-up, three). Visual acuity had improved after treatment in 10 (71.4%) of 14 eyes in whom vision could be recorded. CONCLUSION: Bacillus is an unusual pathogen in the clinical setting of infectious keratitis. The infection is mostly amenable to treatment with commonly used antibiotics, and the final outcome is often satisfactory.

Adolescent↗
PubMed2000

Infectious keratitis in climatic droplet keratopathy.

PURPOSE: To report the ulcer characteristics, microbiologic data, and outcome of infectious keratitis associated with climatic droplet keratopathy (CDK), suggesting that CDK is a predisposing factor for infectious keratitis. METHODS: Medical records of 32 patients (34 eyes) in whom infectious keratitis was seen in association with CDK were retrospectively reviewed. Data were collected regarding the nature of CDK lesions, infiltrate characteristics, organisms isolated, and outcome. RESULTS: CDK was peripheral in 16 (47.1%) eyes, central in 8 (23.5%), and diffuse in 10 (29.4%). The CDK lesions were nodular and elevated in all eyes. The infiltrate was adjacent to the CDK lesions in 28 eyes (82.4%). The infiltrate size (widest dimension) ranged 2-6 mm in 18 eyes (52.9%) and was >6 mm in 7 (20.5%). The infiltrate was full thickness in 15 eyes (44.1%) and was involving up to the middle third of the corneal stroma in another 18 (52.8%). Hypopyon was seen in all. Bacteria were commonly isolated. Staphylococcus epidermidis (six eyes) and Streptococcus pneumoniae (five eyes) were the common bacteria isolated. Resolution with medical treatment was seen in 20 (58.8%) eyes. CONCLUSIONS: CDK is a predisposing factor for infectious keratitis. Treatment should be considered for advanced and nodular lesions, even if they are peripheral, to prevent infectious keratitis.

Adult↗